Radiation generators, such as neutron and X-ray generators, are used in well logging tools to take measurements of a geological formation adjacent a wellbore where hydrocarbon resources are located (e.g., oil and/or natural gas). Neutron generators use deuterium-deuterium (d-d), deuterium-tritium (d-t) or tritium-tritium (t-t) reactions to create neutrons without the use of radioactive materials.
Neutron generators may include a neutron tube and associated electrical components, such as one or more high voltage transformers with a Cockcroft-Walton ladder to produce a high operating voltage. The neutron tube is a sealed envelope made of metal and insulators comprising a gas reservoir, an ion source, an accelerator column and a target. The target may be made of a hydride material. Once released from the reservoir, the gas is ionized in the ion source, and then accelerated in the accelerator column toward the target. A nuclear fusion reaction occurs between the incoming ions and the hydrogen isotope atoms present in the target, causing neutrons to be directed into the geological formation. A radiation detector may detect the radiation from the geological formation resulting form the neutron bombardment, which in turn provides information regarding the composition of the geological formation.